Studies supported are concerned with: 1) induction of infectious virus from virogenic transformed cells; 2) cell surface changes in transformed cells; and 3) the production of a transformed human lympho-reticular cell capable of producing antibody of predetermined specificity continuously. Our studies have established a relationship between DNA breakage, either directly or indirectly, and induction of infectious virus from transformed cells. They further indicate that DNA repair processes are involved and that increased cell permissiveness for viral replication is also involved in the induction process. The secretion/shedding of certain cell surface materials from transformd cells is being studied. Ca ions and Sr ions and lactalbumin hydrolysate increase this process and interferon prevents it. Furthermore, a large proportion of cell PA moves from the rough endoplasmic reticulum to the plasma membrane during cell activation. An EBV transformed human cell line capable of producing anti-tetanus antibody continuously has been established. It has been cloned and has continued to produce antibody for over one year in culture.